Check valves are designed to permit the flow of fluid in one direction while preventing the fluid from flowing in the reverse direction. Conventional check valves utilize a single poppet valve within a body which controls the flow of fluid therethrough. However, conventional poppet valves are likely to become lodged in the interior seat provided by an annular flange within the valve body. When this happens, it is almost impossible to dislodge the poppet valve without dismantling the check valve or utilizing a new fitting. Moreover, conventional valves are difficult to assemble and may include many parts and fasteners. It may also be awkward to assemble and/or repair valves, as different parts can be located on opposite sides of a valve seat or flange formed within the valves.